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src/cpu/o3/probe/elastic_trace.hh (line 88) <http://reviews.gem5.org/r/3027/#comment6413> Brace on next line. src/cpu/o3/probe/elastic_trace.hh (line 92) <http://reviews.gem5.org/r/3027/#comment6414> short int --> PhysRegIndex src/cpu/o3/probe/elastic_trace.hh (line 107) <http://reviews.gem5.org/r/3027/#comment6415> Reference src/cpu/o3/probe/elastic_trace.hh (line 195) <http://reviews.gem5.org/r/3027/#comment6416> Brace on next line. src/cpu/o3/probe/elastic_trace.hh (line 228) <http://reviews.gem5.org/r/3027/#comment6419> The name tempStore sounds strange. Typically if something is temporary, you would want to declare it in the function that is going to make use of it. src/cpu/o3/probe/elastic_trace.hh (line 253) <http://reviews.gem5.org/r/3027/#comment6417> Brace on next line. src/cpu/o3/probe/elastic_trace.hh (line 276) <http://reviews.gem5.org/r/3027/#comment6418> Tick. A value of zero should mean no dependencies. src/cpu/o3/probe/elastic_trace.hh (line 338) <http://reviews.gem5.org/r/3027/#comment6420> Should the type be InstSeqNum? src/cpu/o3/probe/elastic_trace.hh (line 404) <http://reviews.gem5.org/r/3027/#comment6425> Is there any use case where we may not want to write all the records in the trace? src/cpu/o3/probe/elastic_trace.cc (line 78) <http://reviews.gem5.org/r/3027/#comment6421> Will this throw an exception in case we cannot access the file? src/cpu/o3/probe/elastic_trace.cc (lines 104 - 108) <http://reviews.gem5.org/r/3027/#comment6422> How about always enqueuing the event? src/cpu/o3/probe/elastic_trace.cc (line 138) <http://reviews.gem5.org/r/3027/#comment6423> I think this variable is not of any use. src/cpu/o3/probe/elastic_trace.cc (line 356) <http://reviews.gem5.org/r/3027/#comment6424> I think the convention in gem5 is to write (!condition). - Nilay Vaish On Nov. 5, 2015, 9:04 p.m., Curtis Dunham wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > http://reviews.gem5.org/r/3027/ > ----------------------------------------------------------- > > (Updated Nov. 5, 2015, 9:04 p.m.) > > > Review request for Default. > > > Repository: gem5 > > > Description > ------- > > The elastic trace is a type of probe listener and listens to probe points > in multiple stages of the O3CPU. The notify method is called on a probe > point typically when an instruction successfully progresses through that > stage. > > As different listener methods mapped to the different probe points execute, > relevant information about the instruction, e.g. timestamps and register > accesses, are captured and stored in temporary InstExecInfo class objects. > When the instruction progresses through the commit stage, the timing and the > dependency information about the instruction is finalised and encapsulated in > a struct called TraceInfo. TraceInfo objects are collected in a list instead > of writing them out to the trace file one a time. This is required as the > trace is processed in chunks to evaluate order dependencies and computational > delay in case an instruction does not have any register dependencies. By this > we achieve a simpler algorithm during replay because every record in the > trace can be hooked onto a record in its past. The instruction dependency > trace is written out as a protobuf format file. A second trace containing > fetch requests at absolute timestamps is written to a separate protobuf > format file. > > If the instruction is not executed then it is not added to the trace. > The code checks if the instruction had a fault, if it predicated > false and thus previous register values were restored or if it was a > load/store that did not have a request (e.g. when the size of the > request is zero). In all these cases the instruction is set as > executed by the Execute stage and is picked up by the commit probe > listener. But a request is not issued and registers are not written. > So practically, skipping these should not hurt the dependency modelling. > > If squashing results in squashing younger instructions, it may happen that > the squash probe discards the inst and removes it from the temporary > store but execute stage deals with the instruction in the next cycle which > results in the execute probe seeing this inst as 'new' inst. A sequence > number of the last processed trace record is used to trap these cases and > not add to the temporary store. > > The elastic instruction trace and fetch request trace can be read in and > played back by the TraceCPU. > > > Diffs > ----- > > src/proto/packet.proto 854e61d5390e3bee8864848465fab311e95b9759 > src/cpu/o3/probe/ElasticTrace.py PRE-CREATION > src/cpu/o3/probe/SConscript 854e61d5390e3bee8864848465fab311e95b9759 > src/cpu/o3/probe/elastic_trace.hh PRE-CREATION > src/cpu/o3/probe/elastic_trace.cc PRE-CREATION > src/proto/SConscript 854e61d5390e3bee8864848465fab311e95b9759 > src/proto/inst_dep_record.proto PRE-CREATION > > Diff: http://reviews.gem5.org/r/3027/diff/ > > > Testing > ------- > > > Thanks, > > Curtis Dunham > > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
